Gardner was an expert in the new wet-collodion-on-glass-plate photographic process and was manager of Mathew B. Brady's Washington, D.C., portrait studio. He split with Brady in November 1862 and formed his own company, taking with him many of Brady's best photographers. Gardner and his corps, like Brady's, produced a vast photographic documentation of the Civil War.

Here, Union soldiers pose for the camera in deliberately casual attitudes on the front steps of the Confederate commander Robert E. Lee's mansion, which was confiscated by the government in 1861. Laying blame-literally at Lee's doorstep-for the vast suffering of the Civil War, the Union Army in 1864 began to bury its dead on Lee's property in what later became Arlington National Cemetery.